package com.example.spinnertest_314wmy;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private  TextView tvinfo;
    private Spinner spinner;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
        //定义数据源---1
        String[] cities={"北京","上海","天津","大连"};
        //实例实体化适配器，绑定数据源---2
        ArrayAdapter<String> adapter=new ArrayAdapter<String>(
                this,android.R.layout.simple_spinner_item,cities
        );
        //设置Spinner下拉按钮布局---3
        adapter.setDropDownViewResource(
                android.R.layout.simple_spinner_dropdown_item
        );
        //绑定spinner和adapter---4
        spinner.setAdapter(adapter);
        spinner.setPrompt("请选择城市");
        //spinner条目选择事件---5
        spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                tvinfo.setText("您选择的是："+parent.getItemAtPosition(position).toString()
                );
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });


    }
    private void init(){
        tvinfo=(TextView)findViewById(R.id.textView);
        spinner=(Spinner) findViewById(R.id.spinner);

    }
}
